<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Document</title>
	<style>
		div {
			width: 100px;
			height: 100px;
			background-color: red;
		}
		span {
			width: 100px;
			height: 100px;
			display: block;
			background-color: green;
		}
		a {
			width: 80px;
			height: 20px;
			display: inline-block;
			background-color: blue;
			
		}
		
		a:hover{
			background-color: red;

		}
	</style>
</head>
<body>
	<div>123</div>
	<div>123</div>
	<div>123</div>
	<span>aaa</span>
	<span>aaa</span>
	<span>aaa</span>
	<a href="#">baidu</a>
	<a href="#">baidu</a>
	<a href="#">baidu</a>
	
</body>
</html>